System and method for configuring positions in a surgical positioning system

ABSTRACT

A medical navigation system is provided including a surgical positioning system for positioning a payload during a medical procedure. The medical navigation system has a robotic arm having a plurality of joints, the robotic arm forming part of the surgical positioning system and having an end effector for holding the payload, an input device for providing input, and a controller electrically coupled to the robotic arm and the input device. The controller has a processor coupled to a memory and the controller is configured to perform the following during the medical procedure: position the robotic arm in a first position by providing a first positioning signal to the robotic arm; save the first position in the memory as a first saved position in response to a signal received from the input device; position the robotic arm in a second position by providing a second positioning signal to the robotic arm; and return the robotic arm to the first position by loading the first saved position from the memory and providing the first positioning signal to the robotic arm when an input is received from the input device corresponding to a command to return to the first saved position.

TECHNICAL FIELD

The present disclosure is generally related to image guided medicalprocedures, and more specifically to a system and method for configuringpositions in a surgical positioning system.

BACKGROUND

The present disclosure is generally related to image guided medicalprocedures using a surgical instrument, such as an optical scope, anoptical coherence tomography (OCT) probe, a micro ultrasound transducer,an electronic sensor or stimulator, or an access port based surgery.

In the example of a port-based surgery, a surgeon or robotic surgicalsystem may perform a surgical procedure involving tumor resection inwhich the residual tumor remaining after is minimized, while alsominimizing the trauma to the intact white and grey matter of the brain.In such procedures, trauma may occur, for example, due to contact withthe access port, stress to the brain matter, unintentional impact withsurgical devices, and/or accidental resection of healthy tissue. A keyto minimizing trauma is ensuring that the surgeon is aware of what istranspiring in the operating room, has a proper view of the surgicalsite of interest, and has proper control of the surgical positioningsystem without undue distraction.

FIG. 1 illustrates the insertion of an access port into a human brain,for providing access to internal brain tissue during a medicalprocedure. In FIG. 1, access port 12 is inserted into a human brain 10,providing access to internal brain tissue. Access port 12 may includesuch instruments as catheters, surgical probes, or cylindrical portssuch as the NICO Brain Path. Surgical tools and instruments may then beinserted within the lumen of the access port in order to performsurgical, diagnostic or therapeutic procedures, such as resecting tumorsas necessary. The present disclosure applies equally well to catheters,DBS needles, a biopsy procedure, and also to biopsies and/or cathetersin other medical procedures performed on other parts of the body.

In the example of a port-based surgery, a straight or linear access port12 is typically guided down a sulci path of the brain. Surgicalinstruments would then be inserted down the access port 12. Opticaltracking systems, used in the medical procedure, track the position of apart of the instrument that is within line-of-site of the opticaltracking camera. The surgical positioning system will often have acamera mounted thereon and is responsible for maintaining a view of thesurgical site of interest by moving the camera to the proper positions,under the control of the surgeon.

During surgical procedures, a surgeon utilizing an external opticalsystem may want or need to view the surgical site from multiple angles.A problem can occur if it takes a significant amount of time to achievethis or if the surgeon needs to remove tools from the surgical field tomove the optical system between these different angles. In many cases,these viewing angles are known before the procedure or can all bedefined at the start of the procedure.

Conventional systems have not offered good solutions for ensuring that asurgeon has a good view of the surgical site without constantly havingto reconfigure the optical system positioning the camera. It would bedesirable to have a system that helps a surgeon maintain the opticalsystem in the appropriate positions without placing undue burden on thesurgeon during the medical procedure.

SUMMARY

One aspect of the present disclosure provides a medical navigationsystem including a surgical positioning system for positioning a payloadduring a medical procedure. The medical navigation system has a roboticarm having a plurality of joints, the robotic arm forming part of thesurgical positioning system and having an end effector for holding thepayload, an input device for providing input, and a controllerelectrically coupled to the robotic arm and the input device. Thecontroller has a processor coupled to a memory and the controller isconfigured to perform the following during the medical procedure:position the robotic arm in a first position by providing a firstpositioning signal to the robotic arm; save the first position in thememory as a first saved position in response to a signal received fromthe input device; position the robotic arm in a second position byproviding a second positioning signal to the robotic arm; and return therobotic arm to the first position by loading the first saved positionfrom the memory and providing the first positioning signal to therobotic arm when an input is received from the input devicecorresponding to a command to return to the first saved position.

Another aspect of the present disclosure provides a method ofpositioning a payload during a medical procedure in a medical navigationsystem including a surgical positioning system. The medical navigationsystem has a robotic arm, an input device, and a controller. The roboticarm has a plurality of joints and forms part of the surgical positioningsystem and has an end effector for holding the payload. The controllerhas a processor coupled to a memory, the method comprising: positioningthe robotic arm in a first position; saving the first position in thememory as a first saved position in response to a signal received fromthe input device; positioning the robotic arm in a second position; andreturning the robotic arm to the first position by loading the firstsaved position from the memory when an input is received from the inputdevice corresponding to a command to return to the first saved position.

A further understanding of the functional and advantageous aspects ofthe disclosure can be realized by reference to the following detaileddescription and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, withreference to the drawings, in which:

FIG. 1 illustrates the insertion of an access port into a human brain,for providing access to internal brain tissue during a medicalprocedure;

FIG. 2 shows an exemplary navigation system to support minimallyinvasive surgery;

FIG. 3 is a block diagram illustrating a control and processing systemthat may be used in the navigation system shown in FIG. 2;

FIG. 4A is a flow chart illustrating a method involved in a surgicalprocedure using the navigation system of FIG. 2;

FIG. 4B is a flow chart illustrating a method of registering a patientfor a surgical procedure as outlined in FIG. 4A;

FIG. 5 is an exemplary navigation system similar to FIG. 2 illustratingsystem components of an exemplary surgical system that may be used forconfiguring positions of the surgical system;

FIG. 6 is perspective drawing illustrating a conventional end effectorholding a camera;

FIG. 7 is a flow chart is illustrating a method of configuring positionsin a surgical positioning system according to one aspect of the presentdescription; and

FIG. 8 is a block diagram illustrating an example of a virtual realitycomponent according to one aspect of the present description.

DETAILED DESCRIPTION

Various embodiments and aspects of the disclosure will be described withreference to details discussed below. The following description anddrawings are illustrative of the disclosure and are not to be construedas limiting the disclosure. Numerous specific details are described toprovide a thorough understanding of various embodiments of the presentdisclosure. However, in certain instances, well-known or conventionaldetails are not described in order to provide a concise discussion ofembodiments of the present disclosure.

As used herein, the terms, “comprises” and “comprising” are to beconstrued as being inclusive and open ended, and not exclusive.Specifically, when used in the specification and claims, the terms,“comprises” and “comprising” and variations thereof mean the specifiedfeatures, steps or components are included. These terms are not to beinterpreted to exclude the presence of other features, steps orcomponents.

As used herein, the term “exemplary” means “serving as an example,instance, or illustration,” and should not be construed as preferred oradvantageous over other configurations disclosed herein.

As used herein, the terms “about”, “approximately”, and “substantially”are meant to cover variations that may exist in the upper and lowerlimits of the ranges of values, such as variations in properties,parameters, and dimensions. In one non-limiting example, the terms“about”, “approximately”, and “substantially” mean plus or minus 10percent or less.

Unless defined otherwise, all technical and scientific terms used hereinare intended to have the same meaning as commonly understood by one ofordinary skill in the art. Unless otherwise indicated, such as throughcontext, as used herein, the following terms are intended to have thefollowing meanings:

As used herein, the phrase “access port” refers to a cannula, conduit,sheath, port, tube, or other structure that is insertable into asubject, in order to provide access to internal tissue, organs, or otherbiological substances. In some embodiments, an access port may directlyexpose internal tissue, for example, via an opening or aperture at adistal end thereof, and/or via an opening or aperture at an intermediatelocation along a length thereof. In other embodiments, an access portmay provide indirect access, via one or more surfaces that aretransparent, or partially transparent, to one or more forms of energy orradiation, such as, but not limited to, electromagnetic waves andacoustic waves.

As used herein the phrase “intraoperative” refers to an action, process,method, event or step that occurs or is carried out during at least aportion of a medical procedure. Intraoperative, as defined herein, isnot limited to surgical procedures, and may refer to other types ofmedical procedures, such as diagnostic and therapeutic procedures.

Embodiments of the present disclosure provide imaging devices that areinsertable into a subject or patient for imaging internal tissues, andmethods of use thereof. Some embodiments of the present disclosurerelate to minimally invasive medical procedures that are performed viaan access port, whereby surgery, diagnostic imaging, therapy, or othermedical procedures (e.g., minimally invasive medical procedures) areperformed based on access to internal tissue through the access port.

Referring to FIG. 2, an exemplary navigation system environment 200 isshown, which may be used to support navigated image-guided surgery. Asshown in FIG. 2, surgeon 201 conducts a surgery on a patient 202 in anoperating room (OR) environment. A medical navigation system 205comprising an equipment tower, tracking system, displays and trackedinstruments assist the surgeon 201 during his procedure. An operator 203is also present to operate, control and provide assistance for themedical navigation system 205.

Referring to FIG. 3, a block diagram is shown illustrating a control andprocessing system 300 that may be used in the medical navigation system200 shown in FIG. 3 (e.g., as part of the equipment tower). As shown inFIG. 3, in one example, control and processing system 300 may includeone or more processors 302, a memory 304, a system bus 306, one or moreinput/output interfaces 308, a communications interface 310, and storagedevice 312. Control and processing system 300 may be interfaced withother external devices, such as tracking system 321, data storage 342,and external user input and output devices 344, which may include, forexample, one or more of a display, keyboard, mouse, sensors attached tomedical equipment, foot pedal, and microphone and speaker. Data storage342 may be any suitable data storage device, such as a local or remotecomputing device (e.g. a computer, hard drive, digital media device, orserver) having a database stored thereon. In the example shown in FIG.3, data storage device 342 includes identification data 350 foridentifying one or more medical instruments 360 and configuration data352 that associates customized configuration parameters with one or moremedical instruments 360. Data storage device 342 may also includepreoperative image data 354 and/or medical procedure planning data 356.Although data storage device 342 is shown as a single device in FIG. 3,it will be understood that in other embodiments, data storage device 342may be provided as multiple storage devices.

Medical instruments 360 are identifiable by control and processing unit300. Medical instruments 360 may be connected to and controlled bycontrol and processing unit 300, or medical instruments 360 may beoperated or otherwise employed independent of control and processingunit 300. Tracking system 321 may be employed to track one or more ofmedical instruments 360 and spatially register the one or more trackedmedical instruments to an intraoperative reference frame. For example,medical instruments 360 may include tracking markers such as trackingspheres that may be recognizable by a tracking camera 307. In oneexample, the tracking camera 307 may be an infrared (IR) trackingcamera. In another example, a sheath placed over a medical instrument360 may be connected to and controlled by control and processing unit300. In another example, camera 307 may be a video camera.

Control and processing unit 300 may also interface with a number ofconfigurable devices, and may intraoperatively reconfigure one or moreof such devices based on configuration parameters obtained fromconfiguration data 352. Examples of devices 320, as shown in FIG. 3,include one or more external imaging devices 322, one or moreillumination devices 324, a robotic arm 305, one or more projectiondevices 328, and one or more displays 311, and a scanner 309, which inone example may be a three dimensional (3D) scanner.

Exemplary aspects of the disclosure can be implemented via processor(s)302 and/or memory 304. For example, the functionalities described hereincan be partially implemented via hardware logic in processor 302 andpartially using the instructions stored in memory 304, as one or moreprocessing modules or engines 370. Example processing modules include,but are not limited to, user interface engine 372, tracking module 374,motor controller 376, image processing engine 378, image registrationengine 380, procedure planning engine 382, navigation engine 384, andcontext analysis module 386. While the example processing modules areshown separately in FIG. 3, in one example the processing modules 370may be stored in the memory 304 and the processing modules may becollectively referred to as processing modules 370. In some examples,the set of processing engines (370) may reside on a plurality ofindependent control and processing units (300), connected via a network,where the devices (320) may be distributed between the set of controland processing units (300), as well as the data device storage (342).

It is to be understood that the system is not intended to be limited tothe components shown in FIG. 3. One or more components of the controland processing system 300 may be provided as an external component ordevice. In one example, navigation module 384 may be provided as anexternal navigation system that is integrated with control andprocessing system 300.

Some embodiments may be implemented using processor 302 withoutadditional instructions stored in memory 304. Some embodiments may beimplemented using the instructions stored in memory 304 for execution byone or more general purpose microprocessors. Thus, the disclosure is notlimited to a specific configuration of hardware and/or software.

While some embodiments can be implemented in fully functioning computersand computer systems, various embodiments are capable of beingdistributed as a computing product in a variety of forms and are capableof being applied regardless of the particular type of machine orcomputer readable media used to actually effect the distribution.

At least some aspects disclosed can be embodied, at least in part, insoftware. That is, the techniques may be carried out in a computersystem or other data processing system in response to its processor,such as a microprocessor, executing sequences of instructions containedin a memory, such as ROM, volatile RAM, non-volatile memory, cache or aremote storage device.

A computer readable storage medium can be used to store software anddata which, when executed by a data processing system, causes the systemto perform various methods. The executable software and data may bestored in various places including for example ROM, volatile RAM,nonvolatile memory and/or cache. Portions of this software and/or datamay be stored in any one of these storage devices.

Examples of computer-readable storage media include, but are not limitedto, recordable and non-recordable type media such as volatile andnon-volatile memory devices, read only memory (ROM), random accessmemory (RAM), flash memory devices, floppy and other removable disks,magnetic disk storage media, optical storage media (e.g., compact discs(CDs), digital versatile disks (DVDs), etc.), among others. Theinstructions may be embodied in digital and analog communication linksfor electrical, optical, acoustical or other forms of propagatedsignals, such as carrier waves, infrared signals, digital signals, andthe like. The storage medium may be the internet cloud, or a computerreadable storage medium such as a disc.

At least some of the methods described herein are capable of beingdistributed in a computer program product comprising a computer readablemedium that bears computer usable instructions for execution by one ormore processors, to perform aspects of the methods described. The mediummay be provided in various forms such as, but not limited to, one ormore diskettes, compact disks, tapes, chips, USB keys, external harddrives, wire-line transmissions, satellite transmissions, internettransmissions or downloads, magnetic and electronic storage media,digital and analog signals, and the like. The computer useableinstructions may also be in various forms, including compiled andnon-compiled code.

According to one aspect of the present application, one purpose of thenavigation system 205, which may include control and processing unit300, is to provide tools to the neurosurgeon that will lead to the mostinformed, least damaging neurosurgical operations. In addition toremoval of brain tumours and intracranial hemorrhages (ICH), thenavigation system 205 can also be applied to a brain biopsy, afunctional/deep-brain stimulation, a catheter/shunt placement procedure,open craniotomies, endonasal/skull-based/ENT, spine procedures, andother parts of the body such as breast biopsies, liver biopsies,laparoscopic surgery, etc. While several examples have been provided,aspects of the present disclosure may be applied to any suitable medicalprocedure.

Referring to FIG. 4A, a flow chart is shown illustrating a method 400 ofperforming a surgical procedure using a navigation system, such as themedical navigation system 205 described in relation to FIG. 2. At afirst block 402, the surgical plan is imported.

Once the plan has been imported into the navigation system at the block402, the patient is affixed into position using a body holdingmechanism. The head position is also confirmed with the patient plan inthe navigation system (block 404), which in one example may beimplemented by the computer or controller forming part of the equipmenttower of medical navigation system 205.

Next, registration of the patient is initiated (block 406). The phrase“registration” or “image registration” refers to the process oftransforming different sets of data into one coordinate system. Data mayinclude multiple photographs, data from different sensors, times,depths, or viewpoints. The process of “registration” is used in thepresent application for medical imaging in which images from differentimaging modalities are co-registered. Registration is used in order tobe able to compare or integrate the data obtained from these differentmodalities.

Those skilled in the relevant arts will appreciate that there arenumerous registration techniques available and one or more of thetechniques may be applied to the present example. Non-limiting examplesinclude intensity-based methods that compare intensity patterns inimages via correlation metrics, while feature-based methods findcorrespondence between image features such as points, lines, andcontours. Image registration methods may also be classified according tothe transformation models they use to relate the target image space tothe reference image space. Another classification can be made betweensingle-modality and multi-modality methods. Single-modality methodstypically register images in the same modality acquired by the samescanner or sensor type, for example, a series of magnetic resonance (MR)images may be co-registered, while multi-modality registration methodsare used to register images acquired by different scanner or sensortypes, for example in magnetic resonance imaging (MRI) and positronemission tomography (PET). In the present disclosure, multi-modalityregistration methods may be used in medical imaging of the head and/orbrain as images of a subject are frequently obtained from differentscanners. Examples include registration of brain computerized tomography(CT)/MRI images or PET/CT images for tumor localization, registration ofcontrast-enhanced CT images against non-contrast-enhanced CT images, andregistration of ultrasound and CT.

Referring now to FIG. 4B, a flow chart is shown illustrating a methodinvolved in registration block 406 as outlined in FIG. 4A, in greaterdetail. If the use of fiducial touch points (440) is contemplated, themethod involves first identifying fiducials on images (block 442), thentouching the touch points with a tracked instrument (block 444). Next,the navigation system computes the registration to reference markers(block 446).

Alternately, registration can also be completed by conducting a surfacescan procedure (block 450). The block 450 is presented to show analternative approach, but may not typically be used when using afiducial pointer. First, the face is scanned using a 3D scanner (block452). Next, the face surface is extracted from MR/CT data (block 454).Finally, surfaces are matched to determine registration data points(block 456).

Upon completion of either the fiducial touch points (440) or surfacescan (450) procedures, the data extracted is computed and used toconfirm registration at block 408, shown in FIG. 4B.

Referring back to FIG. 4A, once registration is confirmed (block 408),the patient is draped (block 410). Typically, draping involves coveringthe patient and surrounding areas with a sterile barrier to create andmaintain a sterile field during the surgical procedure. The purpose ofdraping is to eliminate the passage of microorganisms (e.g., bacteria)between non-sterile and sterile areas. At this point, conventionalnavigation systems require that the non-sterile patient reference isreplaced with a sterile patient reference of identical geometry locationand orientation.

Upon completion of draping (block 410), the patient engagement pointsare confirmed (block 412) and then the craniotomy is prepared andplanned (block 414).

Upon completion of the preparation and planning of the craniotomy (block414), the craniotomy is cut and a bone flap is temporarily removed fromthe skull to access the brain (block 416). Registration data is updatedwith the navigation system at this point (block 422).

Next, the engagement within craniotomy and the motion range areconfirmed (block 418). Next, the procedure advances to cutting the duraat the engagement points and identifying the sulcus (block 420).

Thereafter, the cannulation process is initiated (block 424).Cannulation involves inserting a port into the brain, typically along asulci path as identified at 420, along a trajectory plan. Cannulation istypically an iterative process that involves repeating the steps ofaligning the port on engagement and setting the planned trajectory(block 432) and then cannulating to the target depth (block 434) untilthe complete trajectory plan is executed (block 424).

Once cannulation is complete, the surgeon then performs resection (block426) to remove part of the brain and/or tumor of interest. The surgeonthen decannulates (block 428) by removing the port and any trackinginstruments from the brain. Finally, the surgeon closes the dura andcompletes the craniotomy (block 430). Some aspects of FIG. 4A arespecific to port-based surgery, such as portions of blocks 428, 420, and434, but the appropriate portions of these blocks may be skipped orsuitably modified when performing non-port based surgery.

When performing a surgical procedure using a medical navigation system205, as outlined in connection with FIGS. 4A and 4B, the medicalnavigation system 205 must acquire and maintain a reference of thelocation of the tools in use as well as the patient in three dimensional(3D) space. In other words, during a navigated neurosurgery, there needsto be a tracked reference frame that is fixed relative to the patient'sskull. During the registration phase of a navigated neurosurgery (e.g.,the step 406 shown in FIGS. 4A and 4B), a transformation is calculatedthat maps the frame of reference of preoperative MRI or CT imagery tothe physical space of the surgery, specifically the patient's head. Thismay be accomplished by the navigation system 205 tracking locations offiducial markers fixed to the patient's head, relative to the staticpatient reference frame. The patient reference frame is typicallyrigidly attached to the head fixation device, such as a Mayfield clamp.Registration is typically performed before the sterile field has beenestablished (e.g., the step 410 shown in FIG. 4A).

FIG. 5 is a diagram illustrating components of an exemplary surgicalsystem that is similar to FIG. 2. FIG. 5 illustrates a navigation system205 having an equipment tower 502, tracking system 504, display 506, anintelligent positioning system 508 and tracking markers 510 used totracked instruments or an access port 12. Tracking system 504 may alsobe considered an optical tracking device, tracking camera, video camera,3D scanner, or any other suitable camera or scanner based system. InFIG. 5, a surgeon 201 is performing a tumor resection through a port 12,using an imaging device 512 (e.g., a scope and camera) to view down theport at a sufficient magnification to enable enhanced visibility of theinstruments and tissue. The imaging device 512 may be an external scope,videoscope, wide field camera, or an alternate image capturing device.The imaging sensor view is depicted on the visual display 506 whichsurgeon 201 uses for navigating the port's distal end through theanatomical region of interest.

An intelligent positioning system 508 comprising an automated arm 514, alifting column 516 and an end effector 518, is placed in proximity topatient 202. Lifting column 516 is connected to a frame of intelligentpositioning system 508. As seen in FIG. 5, the proximal end of automatedmechanical arm 514 (further known as automated arm 514 herein) isconnected to lifting column 516. In other embodiments, automated arm 514may be connected to a horizontal beam, which is then either connected tolifting column 516 or directly to frame of the intelligent positioningsystem 508. Automated arm 514 may have multiple joints to enable 5, 6 or7 degrees of freedom.

End effector 518 is attached to the distal end of automated arm 514. Endeffector 518 may accommodate a plurality of instruments or tools thatmay assist surgeon 201 in his procedure. End effector 518 is shown asholding an external scope and camera, however it should be noted thatthis is merely an example and alternate devices may be used with the endeffector 518 such as a wide field camera, microscope and OCT (OpticalCoherence Tomography), video camera, 3D scanner, or other imaginginstruments. In another example, multiple end effectors may be attachedto the distal end of automated arm 518, and thus assist the surgeon 201in switching between multiple modalities. For example, the surgeon 201may want the ability to move between microscope, and OCT with stand-offoptics. In a further example, the ability to attach a second, moreaccurate, but smaller range end effector such as a laser based ablationsystem with micro-control may be contemplated.

In one example, the intelligent positioning system 508 receives as inputthe spatial position and pose data of the automated arm 514 and target(for example the port 12) as determined by tracking system 504 bydetection of the tracking markers on the wide field camera on port 12.Further, it should be noted that the tracking markers may be used totrack both the automated arm 514 as well as the end effector 518 eithercollectively or independently. It should be noted that a wide fieldcamera 520 is shown in FIG. 5 and that it is connected to the externalscope (e.g., imaging device 512) and the two imaging devices togetherare held by the end effector 518. It should additionally be noted thatalthough these are depicted together for illustration of the diagramthat either could be utilized independently of the other, for examplewhere an external video scope can be used independently of the widefield camera 520.

Intelligent positioning system 508 computes the desired joint positionsfor automated arm 514 so as to maneuver the end effector 518 mounted onthe automated arm's distal end to a predetermined spatial position andpose relative to the port 12. This redetermined relative spatialposition and pose is termed the “Zero Position” where the sensor ofimaging device 512 and port 12 are axially aligned.

Further, the intelligent positioning system 508, optical tracking device504, automated arm 514, and tracking markers 510 may form a feedbackloop. This feedback loop works to keep the distal end of the port 12(located inside the brain) in constant view and focus of the endeffector 518 given that it is an imaging device as the port position maybe dynamically manipulated by the surgeon during the procedure.Intelligent positioning system 508 may also include a foot pedal for useby the surgeon 201 to align the end effector 518 (i.e., holding avideoscope) of automated arm 514 with the port 12. Ensuring that theimaging device 512 and/or wide field camera 520 remain focused on thesurgical site of interest without unduly interfering with the surgeonduring the medical procedure is one of the objectives of the presentapplication and is discussed in more detail below, particularly inconnection with FIGS. 7 and 8.

Referring to FIG. 6, a conventional end effector 518 is shown attachedto automated arm 514. The end effector 518 includes a handle 602 and ascope clamp 604. The scope clamp 604 holds imaging device 512. The endeffector also has wide field camera 520 attached thereto, which in oneexample could be a still camera, video camera, or 3D scanner used tomonitor muscles of the patient for movement, tremors, or twitching.

One aspect of the present disclosure provides a stored position functionthat focuses on the reality that there are some arm positions that willbe constant throughout most procedures and are unlikely to change often.These constant positions can relate to draping, automated arm 514orientation positions (e.g., left or right sided), storage positions,shipping positions, etc. These constant positions may be used beforeand/or after a surgical procedure and this feature may be controlled viaa user interface, a foot pedal, voice control, etc. In one example,these constant positions may be stored as a list of joint anglespertaining to the arm configuration that is related to that particularposition, since the automated arm 514 has a number of joints with anencoder associated with each joint. In one example, the automated arm514 may have six joints or even more. However, the automated arm 514 mayhave any number of joints according to the design criteria of aparticular application. In one example, the automated arm 514 may go toa known position when the automated arm 514 is started up and may beconfigured to toggle between different positions of interest.

In another example, the interface of the automated arm 514 may providethe user with an undo function and a redo function. During a medicalprocedure, the surgeon may wish to undo or redo automated arm 514movements or positions. This feature may both be used to correct anundesired movement of the automated arm 514 or to revisit a previousposition that is clinically relevant. The undo and redo positions may bestored as a list of joint angles pertaining to sequential moves in amovement stack, for example saved in the memory 304 of control andprocessing unit 300 (FIG. 3). The undo and redo feature may be usedduring a procedure but may also be useful during setup and wrap up of amedical procedure. The undo and redo feature may be controlled via afoot pedal, or by other sources of control such as a user interface,voice control, etc. In one example, when a successful move is made usingthe automated arm 514, the surgeon may be provided with the option tosave the move in the memory 304, where the joint angles are saved. Inone example, the joint angles may be saved relative in space to apatient reference based on a trajectory set in the procedure plan orguide.

Another aspect of the present application provides for a dynamic memoryposition. During a procedure, the surgeon may wish to dynamically saveautomated arm 514 movements so that the movements can be revisited at alater time during the same procedure. In one example, the dynamic memorypositions may be stored as joint angles pertaining to the savedautomated arm 514 position. In another example, the dynamic memorypositions may be stored relative to an external frame of reference, suchas the patient.

The dynamic memory position feature may be mainly used during aprocedure as dynamically stored positions but may not be as useful inthe setup and wrap up phases of the procedure. In one example, thedynamic memory position feature may be controlled via a foot pedal, userinterface, voice control, etc. Further, the present application providesfor dynamic allocation of pedal mapping, where a foot pedal may beallocated to trigger the undo feature instead of requiring such input ona user interface of the control and processing unit 300. In one example,stored positions may be recreated by aligning to tools that are held inthe same position from when the desired position was first stored.

Another aspect of the present application provides for surgeons to setstored positions of the automated arm 514 during a medical procedure.These stored positions often provide various perspectives on thesurgical field. Conventionally, a surgeon would have to verbally relayhis or her desire to save the current automated arm 514 position to theclinical applications specialist (e.g., the operator 203 in FIG. 2) whois assisting with manipulating the controls of the medical navigationsystem 205. When a surgeon wants the automated arm 514 to move to one ofthe stored positions, the surgeon tries to recall the number that thespecialist had given that stored position or tries to describe the viewfor the specialist to remember which one it was. This additional dialogintroduces another barrier for changing the position of automated arm514, leading to additional time being spent clarifying the view.Miscommunication between the surgeon and operator would lead to theautomated arm 514 going into a position that the surgeon did not intend.In this case time is unnecessarily wasted and the surgeon's workflow andconcentration would be broken. In fact, communication error in theoperating room is one of the main sources of surgical failures,jeopardizing patient safety. In one example, this problem may beaddressed by streaming stored position view data to an augmentedviewport, such that the surgeon is able to see virtual renderings ofsome or all of the available stored positions. The virtual renderingsmay also include sample snapshots that were taking using the opticssystems such as cameras at that particular stored position. The virtualrenderings may be shown on a display, augmented reality goggles, etc.

Referring now to FIG. 7, a flow chart is showing illustrating a method700 of configuring positions in a surgical positioning system accordingto one aspect of the present description. The method 700 may be executedon a medical navigation system, such as the navigation system 205 (FIG.2) that includes the control and processing unit 300 (FIG. 3), which mayalso include a surgical positioning system, such as intelligentpositioning system 508 (FIG. 5), for positioning a payload during amedical procedure. The medical navigation system includes a robotic arm,such as automated arm 514, having a plurality of joints. The robotic armforms part of the surgical positioning system and has an end effectorfor holding the payload, such as end effector 518 (FIGS. 5 and 6). Themedical navigation system further has an input device for providinginput and a controller (e.g., control and processing unit 300)electrically coupled to the robotic arm and the input device. Thecontroller may have a processor (e.g., processor 302) coupled to amemory (e.g., memory 304). The controller may be configured to performthe method 700.

At a first block 702, the robotic arm (e.g., the automated arm 514) ispositioned in a first position by providing a first positioning signalto the robotic arm. The robotic arm may be placed in the first positioneither under control of the navigation system 205 where a user isproviding an associated input such as through a graphical userinterface, a foot pedal, a voice command, or any other suitable input,or the surgeon may simply grab the robotic arm and manually position therobotic arm in the first position.

Next, at a block 704, the first position is saved in the memory as afirst saved position in response to a signal received from the inputdevice. The first position may be saved in response to a control of thenavigation system 205 where a user is providing an associated input suchas through a graphical user interface, a foot pedal, a voice command, orany other suitable input.

Next, at a block 706, the robotic arm (e.g., the automated arm 514) ispositioned in a second position by providing a second positioning signalto the robotic arm. The robotic arm may be placed in the second positioneither under control of the navigation system 205 where a user isproviding an associated input such as through a graphical userinterface, a foot pedal, a voice command, or any other suitable input,or the surgeon may simply grab the robotic arm and manually position therobotic arm in the second position.

Next, at a block 708, the robotic arm may be returned to the firstposition by loading the first saved position from the memory andproviding the first positioning signal to the robotic arm when anassociated input is received from the input device corresponding to acommand to return to the first saved position. The input device mayinclude a keyboard or mouse connected to the navigation system 205.Input may be provided, such as through a graphical user interface, afoot pedal, a voice command, or any other suitable input.

In one example, the first saved position may be defined by encoder jointangles that are saved, where one angle is saved for each encoderassociated with each of the plurality of joints. In one example, theautomated arm may have six degrees of freedom, six joints, and sixassociated encoders. However, any suitable number of joints and encodersmay be used according to the design criteria of a particularapplication.

In one example, the input device may include any of a foot pedal, amicrophone providing voice input, a touch sensitive overlay on thedisplay, a mouse, and/or a keyboard. In one example, the payloadincludes a camera held by the end effector, such as the camera 307, 512,or 520, and electrically coupled to the controller, or a surgical toolheld by the end effector.

In one example, the first position is manually positioned a first timebased on input provided to the medical navigation system. The input mayinclude a surgeon physically moving the robotic arm to the firstposition or the surgeon moving the robotic arm to the first position byproviding input using the input device.

Returning to FIG. 7, at a block 710, the robotic arm (e.g., theautomated arm 514) is positioned in a third position by providing athird positioning signal to the robotic arm. The robotic arm may beplaced in the third position either under control of the navigationsystem 205 where a user is providing an associated input such as througha graphical user interface, a foot pedal, a voice command, or any othersuitable input, or the surgeon may simply grab the robotic arm andmanually position the robotic arm in the first position.

Next, at a block 712, the third position is saved in the memory as asecond saved position in response to a signal received from the inputdevice. The third position may be saved in response to a control of thenavigation system 205 where a user is providing an associated input suchas through a graphical user interface, a foot pedal, a voice command, orany other suitable input.

Next, at a block 714, the robotic arm (e.g., the automated arm 514) ispositioned in a fourth position by providing a fourth positioning signalto the robotic arm. The robotic arm may be placed in the fourth positioneither under control of the navigation system 205 where a user isproviding an associated input such as through a graphical userinterface, a foot pedal, a voice command, or any other suitable input,or the surgeon may simply grab the robotic arm and manually position itin the fourth position.

Next, at a block 716, the robotic arm may be returned to either thefirst saved position or the second saved position by loading the firstsaved position or the second saved from the memory and providing eitherthe first or second positioning signal to the robotic arm when anassociated input is received from the input device corresponding to acommand to return to the first or second saved position. The inputdevice may include a keyboard or mouse connected to the navigationsystem 205, input such as through a graphical user interface, a footpedal, a voice command, or any other suitable input.

In one example, each of the first and second saved positions correspondsto a tool held by the end effector and the controller may be furtherconfigured to automatically position the robotic arm in one of the firstand second saved positions when the corresponding tool is placed in theend effector. For example, if a probe is placed in the end effector, thenavigation system 205 may automatically identify that the probe is inthe end effector and automatically go to a corresponding position, suchas the first saved position. Any saved position may correspond to anysuitable tool, depending on the design criteria of a particularapplication and any user input to the navigation system 205.

While the example of a first and second saved position is providedabove, any suitable number of saved positions may be used according tothe requirements of the procedure being performed with the medicalnavigation system 205.

In another example, the medical navigation system 205 may have atracking system (e.g., tracking system 321 interfacing with devices suchas camera 307 or 3D scanner 309) electrically coupled to the controller.The first saved position or the second saved position may be definedrelative to a position of a patient determined by the tracking system.The tracking system may be an optical tracking system having a camerafor viewing optical tracking markers attached to the patient, a 3Dscanning tracking system having a 3D scanner for tracking the patient,an electromagnetic tracking system having an electromagnetic sensor fortracking electromagnetic markers on the patient, or any other suitabletype of tracking system.

In yet another example, stored positions may automatically propagate andbe saved, at least temporarily, from a preplanned trajectory from thenavigation system 205 when using a tracking camera and patientreference. In another example, when the robotic arm is automaticallyfollowing a trajectory based on the reference to the patient, at leastsome of the significant positions along this trajectory mayautomatically be saved as stored positions for use later in theprocedure.

Referring now to FIG. 8, a block diagram is shown illustrating anexample of a virtual reality component view 800 according to one aspectof the present description. In one example, the medical navigationsystem 205 may have an augmented reality component for providing a viewof saved positions including the first saved position to a surgeon,thereby allowing the surgeon to easily select between saved positions.As shown in FIG. 8, a head of the patient 202 is shown. Relative topatient 202, the view 800 shows a current position 802 of the automatedarm 514, position 804 of the first saved position, and a position 806 ofthe second saved position. The augmented reality component may include adisplay, such as display 311, electrically coupled to the controller fordisplaying graphical illustrations of the saved positions to thesurgeon, which makes it much easier for the surgeon to recall andidentify which saved position he wishes to choose. In another example,the augmented reality component may include a headset electricallycoupled to the controller for displaying graphical illustrations of thesaved positions to the surgeon. While a display and a headset aredescribed as examples, any suitable device may be used to convey theinformation to the surgeon.

In another example, the controller may be configured to execute a redocommand to return the automated arm 514 to the first position by loadingthe first saved position from the memory when an input is received fromthe input device corresponding to the redo command. In another example,the controller may be configured to execute the undo command to returnthe automated arm to a previous position from a subsequent position byperforming previous movements in reverse even when the previous positionhas not been saved in response to receipt of an input corresponding tothe undo command. In other words, the navigation system mayautomatically save some or all of previous positions in memory, at leasttemporarily, in case the surgeon wishes to revisit these positions at alater time. The redo and/or undo commands may be triggered with anysuitable input, including through a graphical user interface, a footpedal, or a voice command.

The specific embodiments described above have been shown by way ofexample, and it should be understood that these embodiments may besusceptible to various modifications and alternative forms. It should befurther understood that the claims are not intended to be limited to theparticular forms disclosed, but rather to cover all modifications,equivalents, and alternatives falling within the spirit and scope ofthis disclosure.

We claim:
 1. A medical navigation system including a surgicalpositioning system for positioning a payload during a medical procedure,the medical navigation system comprising: a robotic arm having aplurality of joints, the robotic arm forming part of the surgicalpositioning system and having an end effector for holding the payload;an input device for providing input; and a controller electricallycoupled to the robotic arm and the input device, the controller having aprocessor coupled to a memory, the controller configured to perform thefollowing during the medical procedure: position the robotic arm in afirst position by providing a first positioning signal to the roboticarm; save the first position in the memory as a first saved position inresponse to a signal received from the input device; position therobotic arm in a second position by providing a second positioningsignal to the robotic arm; and return the robotic arm to the firstposition by loading the first saved position from the memory andproviding the first positioning signal to the robotic arm when an inputis received from the input device corresponding to a command to returnto the first saved position.
 2. The medical navigation system accordingto claim 1, wherein the first saved position is defined by encoder jointangles for each of the plurality of joints.
 3. The medical navigationsystem according to claim 1, wherein the input device includes at leastone of a foot pedal, a microphone providing voice input, a touchsensitive overlay on the display, a mouse, and a keyboard.
 4. Themedical navigation system according to claim 1, wherein the payloadincludes at least one of a camera held by the end effector andelectrically coupled to the controller and a surgical tool held by theend effector.
 5. The medical navigation system according to claim 1,wherein the first position is manually positioned a first time based oninput provided to the medical navigation system, including at least oneof a surgeon physically moving the robotic arm to the first position andthe surgeon moving the robotic arm to the first position by providinginput using the input device.
 6. The medical navigation system accordingto claim 1, the controller further being configured to: position therobotic arm in a third position by providing a third positioning signalto the robotic arm; save the third position in the memory as a secondsaved position in response to a signal received from the input device;position the robotic arm in a fourth position by providing a fourthpositioning signal to the robotic arm; and return the robotic arm to oneof the first saved position and the second saved position by loading thecorresponding first or second saved position from the memory when aninput is received from the input device corresponding to a command toreturn to one of the first and second saved positions.
 7. The medicalnavigation system according to claim 6, wherein each of the first andsecond saved positions corresponds to a tool held by the end effectorand the controller is further configured to automatically position therobotic arm in one of the first and second saved positions when thecorresponding tool is placed in the end effector.
 8. The medicalnavigation system according to claim 1 further comprising a trackingsystem electrically coupled to the controller wherein the first savedposition is defined relative to a position of a patient determined bythe tracking system.
 9. The medical navigation system according to claim8, wherein the tracking system is selected from the group consisting ofan optical tracking system having a camera for viewing optical trackingmarkers attached to the patient, a 3D scanning tracking system having a3D scanner for tracking the patient, and an electromagnetic trackingsystem having an electromagnetic sensor for tracking electromagneticmarkers on the patient.
 10. The medical navigation system according toclaim 1 further comprising an augmented reality component for providinga view of saved positions including the first saved position to asurgeon, thereby allowing the surgeon to easily select between savedpositions.
 11. The medical navigation system according to claim 10,wherein the augmented reality component includes a display electricallycoupled to the controller for displaying graphical illustrations of thesaved positions to the surgeon.
 12. The medical navigation systemaccording to claim 10, wherein the augmented reality component includesa headset communicating with the controller for displaying graphicalillustrations of the saved positions to the surgeon.
 13. The medicalnavigation system according to claim 1, wherein the controller isfurther configured to: execute a redo command to return the robotic armto the first position by loading the first saved position from thememory when an input is received from the input device corresponding tothe redo command.
 14. The medical navigation system according to claim1, wherein the controller is further configured to, when an input isreceived from the input device corresponding to an undo command: executethe undo command to return the robotic arm to a previous position from asubsequent position by performing previous movements in reverse evenwhen the previous position has not been explicitly saved.
 15. A methodof positioning a payload during a medical procedure in a medicalnavigation system including a surgical positioning system, the medicalnavigation system having a robotic arm, an input device, and acontroller, the robotic arm having a plurality of joints and formingpart of the surgical positioning system and having an end effector forholding the payload, the controller having a processor coupled to amemory, the method comprising: positioning the robotic arm in a firstposition; saving the first position in the memory as a first savedposition in response to a signal received from the input device;positioning the robotic arm in a second position; and returning therobotic arm to the first position by loading the first saved positionfrom the memory arm when an input is received from the input devicecorresponding to a command to return to the first saved position. 16.The method according to claim 15, wherein the first saved position isdefined by encoder joint angles for each of the plurality of joints. 17.The method according to claim 15, wherein the input device includes atleast one of a foot pedal, a microphone providing voice input, a touchsensitive overlay on a display, a mouse, and a keyboard.
 18. The methodaccording to claim 15, wherein the payload includes at least one of acamera held by the end effector and electrically coupled to thecontroller and a surgical tool held by the end effector.
 19. The methodaccording to claim 15, wherein the first position is manually positioneda first time based on input provided to the medical navigation system,including at least one of a surgeon physically moving the robotic arm tothe first position and the surgeon moving the robotic arm to the firstposition by providing input using the input device.
 20. The methodaccording to claim 15, further comprising: positioning the robotic armin a third position; saving the third position in the memory as a secondsaved position in response to a signal received from the input device;positioning the robotic arm in a fourth position; and returning therobotic arm to one of the first saved position and the second savedposition by loading the corresponding first or second saved positionfrom the memory when an input is received from the input devicecorresponding to a command to return to one of the first and secondsaved positions.